The growth of most aquatic vegetation, such as algae, is harmful to the ecology of a body of water. It substantially contributes to the eutrophication of the body of water and this eventually leads to the extinction of all life from the water and to the formation of a slimy overgrowth. This renders the water unsightly and useless for practically any purpose. Harvesting of aquatic vegetation growth, along with the building of sewers to prevent nutrient run-off into the water, are among the principal measures to save bodies of water from eutrophication.
Aquatic weed infestations adversely effect boating, drainage, irrigation, fish and wildlife, and recreation. Heavy infestations may block or impede boat movement, damage propellers, or block engine cooling systems. Water flow in drainage and irrigation ditches may be seriously retarded by aquatic plants.
Infestations may render the area unsuitable for fish by exhausting dissolved oxygen in basic food production, by restricting the movement of fish or by rendering shallow water unsuitable for spawning.
Excessive growth of aquatic plants interferes with recreational use of water in lakes and ponds. In addition to preventing access to an the use of water for hunting and fishing, aquatic plants often preclude boating, swimming, skiing and other water oriented activities reducing the recreational value of water resources.
Improving water quality by controlling aquatic weeds will restore the balance of the body of water and increase the value of waterside property.
The harvesting of aquatic vegetation is carried out practically exclusively with clumsy, inefficient machinery which is generally very large and provides its own flotation. The operator of the large machinery usually rides the machine itself in the water. Alternative means for the removal of aquatic vegetation growth includes various toxic chemicals, but these are expensive and have their own dangerous ecological side effects. There is no simple, relatively small machinery available to small riparian owners for the removal of aquatic vegetation growth.
There are various smaller aquatic vegetation cutting devices disclosed in the prior art, however, none of them appear to have been commercially realized. U.S. Pat No. 3,499,271 shows an underwater weed cutter attachment for the drive shaft of an outboard motor and the propeller of the motor is, in turn, attached to the drive shaft protruding from the cutter attachment. Two sets of flat reciprocating blades are powered from the drive shaft of the outboard motor through a power transmission.
U.S. Pat. No. 3,601,956 discloses a hand operated underwater cutter in which double edge blades are attached to opposite sides of a header which is mounted at the end of a shaft which permits the immersion of the header and the blades into th water. The blades pivot away from the direction of movement to permit uncut weeds from slipping out of the end of the blade to prevent it from fouling.
French patent No. 1,051,916; and Swiss patents Nos. 125,643 and 126,354 also describe simple, rudimentary aquatic weed cutting devices or features thereof.